Pitchers add depth to rotation; Arrieta slowed by discomfort

MESA, Ariz. -- The Cubs officially signed free-agent pitchers Jason Hammel and James McDonald on Thursday and may need at least one or both for the rotation because Jake Arrieta will be behind schedule this spring after experiencing some tightness in his right shoulder.

Arrieta was projected as the club's fourth starter this season. Cubs general manager Jed Hoyer said Thursday that the right-hander had some discomfort when he started throwing in the winter.

"We've re-started his throwing program, but he'll be a little bit late into camp as far as throwing bullpens and getting into games," Hoyer said. "No timetables yet, but he is throwing and feeling good now. That was something in the back of our minds as we went through this and added some pitching depth."

Hammel signed a one-year, $6 million deal, while McDonald signed a one-year, $1 million non-guaranteed contract that does include incentives.

Hammel, 31, posted some of the best numbers of his career in 2012, going 8-6 with a 3.43 ERA in 118 innings over 20 starts for the Orioles. He was Baltimore's Opening Day starter in 2013 but took a step back last season, finishing 7-8 with a 4.97 ERA in 139 1/3 innings over 26 appearances (23 starts). Part of the problem may have been injury as Hammel was on the disabled list because of tenderness in his right forearm.

From 2009-11, Hammel proved to be a durable back-of-the-rotation starter with the Rockies, throwing at least 170 innings in each of those three seasons while posting a 27-30 record and 4.63 ERA, inflated by hitter-friendly Coors Field. Overall in parts of eight big league seasons with the Rays, Rockies and Orioles, the right-hander has gone 49-59 with a 4.80 ERA in 989 1/3 innings.

"He's a guy who's had some success in some pretty difficult places," Hoyer said of Hammel. "He started in [St. Petersburg], went to Colorado and had some success in Coors Field and then obviously had some success in the American League East with Baltimore. We're excited to get him."

McDonald, 29, was limited to six games last season with the Pirates because of shoulder issues, and posted a 2-2 record and 5.76 ERA. The right-hander was designated for assignment in September and outrighted to Triple-A Indianapolis but refused that assignment and elected free agency.

"James is a guy who we've really liked the stuff," Hoyer said. "He's dealt with some injuries over the last couple years, but he worked really hard this winter. We've seen him throw a number of times over the course of the winter and he looks healthy."

The last two seasons, the Cubs have signed free agents Paul Maholm and Scott Feldman and then flipped them at the Trade Deadline for prospects. If Hammel and McDonald have success, that may be their fate as well.

The Cubs opened space on the 40-man roster on Wednesday for the two pitchers. The Reds claimed right-handed pitcher Brett Marshall off waivers, while the Twins claimed lefty Brooks Raley. Chicago's 40-man roster was at 40 prior to those moves.

Marshall, 23, never pitched for the Cubs. He was was claimed in December off the Yankees' roster. The right-hander did appear in three games last season with New York. Raley, 25, a sixth-round Draft pick in 2009, appeared in 14 games with the Cubs over two seasons. He was used as a starter in 2012 with the big league team but pitched in relief last season, compiling a 5.14 ERA in nine games.